Recently, in an optical recording medium, there has been a greater demand for providing a surface opposite to a surface on which optical writing/reading is performed, with an ink receiving layer (lebel printing surface) and printing images or literatures representing a recorded content in the medium with an ink jet method so as to arrange the optical recording medium.
As an ink used for an ink jet recording method, there is usually used an aqueous one and, in many cases, a polyhydric alcohol or the like is added to this ink in order to prevent clogging of a nozzle.
On the other hand, as a substrate on which recording is made in the ink jet recording method, there have hitherto been used a normal paper, and a hydrophilizied paper such as a specialty paper for ink jet which is provided with a porous ink receiving layer. As such an ink receiving layer, there are described, for example, the use of a water-soluble high polymer of poly (vinyl alcohol) and polyacrylic acid in Japanese Laid-open Patent Publication No.60-168651/1985, the use of hydroxyethyl cellulose in Japanese Laid-open Patent Publication No.60-262685/1985, the use of a mixture of carboxymethyl cellulose and polyethylene oxide in Japanese Laid-open Patent Publication No.61-181679/1986, and the use of a mixture of water-soluble cellulose and poly (vinylpyrrolidone) in Japanese Laid-open Patent Publication No.61-193879/1986. Since the water-soluble polymers described in these laid open publications are very hydrophilic, they have affinity with a hydrophilic substrate such as a paper and the like and, when an ink receiving layer composed of these water-soluble polymers is provided on the surface of a hydrophilic substrate, there arises no problem on adhesion between the substrate and the ink receiving layer.
However, for example, the water-soluble polymers described in the aforementioned laid open publications have little affinity with substrates having the surface of strong hydrophobicity such as an ultraviolet-curing resin and the like frequently used in a protecting membrane for the optical recording medium. For that reason, when an ink receiving layer composed of these water-soluble polymers is provided on the surface of a hydrophobic substrate, adhesion between the hydrophobic substrate and the ink receiving layer is worse and, after laminated, they are easily peeled and, additionally, since the ink receiving layer itself has the lower water-resistance, there are occurrence of an ink blot caused by a water droplet after printing and stickiness of the surface, which leads to a problem of practical use.